The process of manufacturing integrated circuit (IC) packages generally begins with press stamping or etching of a leadframe sheet, which is generally a copper sheet. A typical leadframe sheet has several separate panels, and each panel includes an array of integrally connected leadframes. While the leadframes are still integrally connected on the leadframe sheet, integrated circuit dies are attached to each of the leadframes. These dies are then electrically attached to the corresponding leadframes, as by wire bonding.
In the next procedure, the leadframes in each panel portion of the leadframe sheet and the associated dies are encapsulated in molten mold compound. The mold compound cures to become a hard plastic block that encases the entire leadframe panel and the associated dies while leaving portions of each leadframe exposed through the mold compound.
The next operation performed is cutting (“singulating” or “dicing”) the mold compound blocks that encapsulate each leadframe panel. During singulation, the encapsulated block covering each panel is cut up into multiple smaller blocks. To accomplish this, the leadframe sheet is placed on the top surface of a saw chuck table. A vacuum is applied through holes in the saw chuck table top plate. The vacuum securely holds the leadframe sheet to the saw chuck table top plate as the blocks are sawed along multiple “saw streets” by a rotating saw blade. The saw streets are straight lines arranged in a rectangular grid. The grid rectangles correspond to the individual IC package units in each leadframe panel. Various other plating and lead forming steps are performed on the individual IC packages after singulation.